Image forming apparatus forming images based on received image data, terminal device transmitting image data to the image forming apparatus, image forming system including image forming apparatus and terminal device, and non-transitory computer readable medium

ABSTRACT

A multifunction peripheral ( 100 ) is connected to a terminal device ( 200 ) via a communication link, receives image data transmitted from the terminal device ( 200 ) and forms an image based on the image data. Further, the multifunction peripheral ( 100 ) detects the state of connection of the communication link and thereby detects whether or not communication with the terminal device ( 200 ) is interrupted. If interruption of communication is detected while image data transmitted from the terminal device is being received, the multifunction peripheral suspends the unfinished state of reception of image data.

TECHNICAL FIELD

The present invention relates to an image forming apparatus and, morespecifically, to an image forming apparatus constituting an imageforming system together with a terminal device connected via acommunication link.

BACKGROUND ART

As one type of information equipment, image forming apparatuses havebeen introduced to many places of business (companies and offices). Suchan image forming apparatus is connected to a terminal device through acommunication link, receives image data transmitted from the terminaldevice, and prints an image based on the image data.

In an image forming system including a terminal device and an imageforming apparatus, sometimes communication fails by some cause or otherwhile image data is being transmitted from the terminal device to theimage forming apparatus. In such a situation, transmission of the imagedata from the terminal device to the image forming apparatus is stoppedand, therefore, printing cannot be executed.

Recently, it is becoming more popular to use wireless transmission forprinting by the image forming apparatus. When image data is to betransferred from the terminal device to the image forming apparatusthrough a wireless link, it is difficult to maintain satisfactorycommunication between the terminal device and the image formingapparatus if the state of wireless link (for example, radio wavecondition) deteriorates. Then, satisfactory transfer of image data fromthe terminal device to the image forming apparatus becomes impossible.

Patent literature 1 as indicated below discloses an informationprocessing apparatus connected to a printing apparatus through awireless link. The information processing apparatus transmits print datato the printing apparatus, and instructs execution of printing of theprint data that has been transmitted to the printing apparatus. Further,the information processing apparatus detects the status of wirelesslink, and controls the operation of instructing print execution inaccordance with the detected link status. Specifically, if the status ofwireless communication is bad, the information processing apparatusstops the operation of instructing execution of printing.

According to Patent Literature 1, since the operation of instructingexecution of printing is stopped by the information processing apparatusif the status of wireless link is unsatisfactory, it is possible toprevent execution of printing when transfer of print data to theprinting apparatus fails.

CITATION LIST Patent Literature Patent Literature 1: Japanese PatentLaying-Open No. 2011-123592 SUMMARY OF INVENTION Technical Problem

When the operation of instructing print execution is stopped by theinformation processing apparatus of Patent Literature 1, the process ofexecuting printing ends, and therefore, if communication is interrupted,it is necessary to wait until good link status is recovered and to startdata communication again. Thus, restart of communication requires muchtime and trouble.

The present invention was made to solve the above-described problem, andan object of the present invention is to provide an image formingapparatus that can save the time and trouble when restartingcommunication, even if communication is interrupted during transfer ofimage data.

Solution to Problem

In order to attain the above-described object, the present inventionprovides: an image forming apparatus, connected to a terminal devicethrough a communication link, receiving image data transmitted from theterminal device and forming an image based on the image data, including:link state detecting means for detecting whether communication with theterminal device is interrupted or not, by detecting a state ofcommunication link; and data suspending means, responsive to detectionby the link state detecting means of an interruption of communication,for suspending an unfinished state of reception of the image data.

The image forming apparatus detects whether or not communication withthe terminal device is interrupted. If it is detected that communicationis interrupted during reception of image data transmitted from theterminal device, the image forming apparatus suspends the state of imagedata reception that is halfway through. Specifically, if communicationis interrupted, the image forming apparatus records the unfinished state(communication up to the interrupted point). Therefore, whencommunication is resumed (recovered), it is possible for the imageforming apparatus to receive the image data from the middle. Thus, evenif communication is interrupted during reception of image data, it ispossible to receive the data transmission from the middle and,therefore, time and labor at the restart can be saved.

Preferably, the communication link includes a wireless link; and theimage forming apparatus further includes wireless communication meansfor communicating with the terminal device through the wireless link.

While image data transmitted from the terminal device is being received,if the user using the terminal device walks away with the terminaldevice and goes out of the range of wireless communication, transmissionis stopped. Then, the image forming apparatus of the present inventionsuspends the interrupted state of communication. Therefore, when theuser comes back and enters the range of wireless communication andcommunication restarted, data communication can be resumed from themiddle. Thus, the time and labor at the time of restart can efficientlybe saved.

More preferably, the image forming apparatus further includes: timemeasuring means for measuring time elapsed after the detection of theinterruption of communication by the link state detecting means; meansfor receiving, when the data suspending means is suspending anunfinished state of communication and communication is resumed within aprescribed time period from the detection of the interruption ofcommunication by the link state detecting means, the image data from thesuspended unfinished state; and means for discarding the received imagedata, when the data suspending means is suspending an unfinished stateof communication and communication is not resumed within a prescribedtime period from the detection of the interruption of communication bythe link state detecting means.

It is likely that data transmission (transfer) is resumed, if it iswithin a prescribed time period from when interruption of communicationis detected by the link state detecting means. Therefore, it ispreferable that the image forming apparatus is configured to be able toreceive image data from the suspended unfinished state of communication,if the communication restarts within a prescribed time period from whenthe link state detecting means detected the interruption ofcommunication. On the other hand, if the prescribed time period passedfrom when the link state detecting means detected the interruption ofcommunication, it is unlikely that the data transmission restarts, or itis more likely that the data transmission is started anew. Therefore, itis preferable that the image forming apparatus is configured to discardthe received image data if communication is not resumed within aprescribed time period from when the link state detecting means detectedthe interruption of communication. Thus, waste of memory area forstoring the image data can be prevented.

More preferably, the image forming apparatus further includes means forstarting image formation, after reception of image data is completed.

The image forming apparatus starts image formation (printing) after thereception of image data is completed. In other words, the image formingapparatus does not start printing until the data is fully received.Therefore, even when communication is stopped during transfer of theimage data and the data communication is restarted from the middle whenthe communication is resumed, print outputs will not be scattered andlost (separated). This also saves time and labor at the time of restart.

According to a second aspect, the present invention provides a terminaldevice, connected to an image forming apparatus through a wireless link,including: transmitting means for transmitting image data to the imageforming apparatus; link state detecting means for detecting whethercommunication with the image forming apparatus is interrupted or not, bydetecting a state of wireless link; and data suspending means,responsive to detection by the link state detecting means of aninterruption of communication while image data is being transmitted tothe image forming apparatus, for suspending an unfinished state oftransmission of the image data.

The terminal device detects whether or not the communication with theimage forming apparatus is interrupted. If it detects interruption ofcommunication while image data is being transmitted to the image formingapparatus, the terminal device suspends the unfinished state of imagedata transmission. Therefore, when communication is resumed (recovered),it is possible for the terminal device to transmit the image data fromthe middle. Thus, even if communication is interrupted duringtransmission of image data, it is possible to restart the datatransmission from the middle when the communication is resumed and,therefore, time and labor at the time of restart can be saved.

Preferably, the terminal device further includes: wireless link statedetecting means for detecting a state of wireless link; and notifyingmeans for giving an alarm notice related to the state of wireless linkin accordance with the state of wireless link detected by the wirelesslink state detecting means while image data is being transmitted to theimage forming apparatus.

By way of example, if the radio wave condition for wireless linkdeteriorates, the terminal device notifies the user of the state ofwireless link that the radio wave condition is bad, as an alarm relatedto the state of wireless link. By this notification, the user recognizesthe state of wireless link (for example, that the radio wave conditionis bad). This may urge the user to move to a range of better radio wavecondition, and as a result, may ensure improved radio wave condition.

More preferably, the terminal device further includes inquiry means,responsive to detection of the interruption of communication by the linkstate detecting means while image data is being transmitted to the imageforming apparatus, for inquiring whether an unfinished state ofcommunication is to be suspended or not.

Since an inquiry is made as to whether the unfinished state ofcommunication is to be suspended, it becomes possible for the user toselect whether or not the unfinished state of communication is to besuspended. The user can suspend the unfinished state of communicationonly when he/she wishes to do so.

According to a third aspect, the present invention provides an imageforming system, including a terminal device transmitting image data, andan image forming apparatus connected to the terminal device through acommunication link, receiving the image data transmitted from theterminal device and forming an image based on the image data, including:link state detecting means for detecting whether communication betweenthe terminal device and the image forming apparatus is interrupted ornot, by detecting a state of communication link; and data suspendingmeans, responsive to detection by the link state detecting means of aninterruption of communication while image data is being transmitted fromthe terminal device to the image forming apparatus, for suspending anunfinished state of communication.

The image forming system detects whether or not the communicationbetween the image forming apparatus and the terminal device isinterrupted. If it is detected that the communication is interruptedduring transmission of image data from the terminal device to the imageforming apparatus, the present image forming system suspends theinterrupted state. Specifically, the present image forming systemrecords the unfinished state of communication (up to the time point whenthe communication is stopped). Therefore, when communication is resumed(recovered), it is possible to restart data transfer from the unfinishedstate. This saves time and labor at the time of restart.

Preferably, the communication link includes a wireless link; and each ofthe terminal device and the image forming apparatus further includeswireless communication means for communicating with each other in awireless manner through the wireless link.

While image data is being transmitted from the terminal device to theimage forming apparatus, if the user using the terminal device walksaway with the terminal device and goes out of the range of wirelesscommunication, transmission is stopped. In such a situation, the imageforming system of the present invention suspends the unfinished state ofcommunication. Therefore, when the user comes back and enters the rangeof wireless communication and communication restarts, data communicationcan be resumed from the middle. Thus, the time and labor at the time ofrestart can efficiently be saved.

Further, when image data of a large data size is to be transmitted fromthe terminal device to the image forming apparatus by a wireless link,with a conventional system, the user using the terminal device must staywithin the range allowing wireless communication. If the user shouldmove and go out of the communicable range, the communication is stoppedand the data communication must be started anew. In contrast, by thepresent image forming system, even if the user goes out of the rangeallowing wireless communication, data communication can be resumed fromthe middle and, hence, the user can move freely while holding theterminal device.

More preferably, the data suspending means includes means for enablingthe image forming apparatus to suspend an unfinished state of receivingthe image data.

The user suspends the unfinished state of reception of the image data.Therefore, when the communication is resumed, the image formingapparatus can receive the image data from the middle.

More preferably, the data suspending means includes means for enablingthe terminal device to suspend an unfinished state of transmitting theimage data and means for enabling the image forming apparatus to suspendan unfinished state of receiving the image data.

The terminal device suspends the unfinished state of image datatransmission. Therefore, when communication is resumed, it is possiblefor the terminal device to transmit the image data from the middle. Theimage forming apparatus suspends the unfinished state of image datareception. Therefore, when communication is resumed, it is possible forthe image forming apparatus to receive the image data from the middle.

According to a fourth aspect, the present invention provides a computerprogram, causing a computer connected to an image forming apparatusthrough a communication link to function as: means for transmittingimage data to the image forming apparatus; link state detecting meansfor detecting whether communication with the image forming apparatus isinterrupted or not, by detecting a state of the communication link; anddata suspending means, responsive to detection by the link statedetecting means of an interruption of communication while image data isbeing transmitted to the image forming apparatus, for suspending anunfinished state of transmission of the image data.

Advantageous Effects of Invention

As described above, by the present invention, an image forming apparatusand the like that saves time and labor when communication is resumed,even if communication is interrupted during transfer of image data, caneasily be obtained.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an overall configuration of an image forming system inaccordance with an embodiment of the present invention.

FIG. 2 shows the image forming system in accordance with an embodimentof the present invention (in a state in which communication is about tobe lost).

FIG. 3 shows the image forming system in accordance with an embodimentof the present invention (in a state in which communication is lost).

FIG. 4 is a control block diagram showing a hardware configuration of amultifunction peripheral shown in FIG. 1

FIG. 5 is a control block diagram showing a hardware configuration ofthe terminal device shown in FIG. 1.

FIG. 6 shows an example of a screen image allowing wireless settingsdisplayed on an operation unit of the multifunction peripheral.

FIG. 7 shows an example of a screen image allowing wireless settingsdisplayed on a user I/F of the terminal device.

FIG. 8 is a flowchart representing a control structure of a programexecuted by the terminal device shown in FIG. 1.

FIG. 9 shows a detailed flow of step S1000 of FIG. 8.

FIG. 10 shows an example of a dialogue displayed on the user I/F of theterminal device.

FIG. 11 shows an example of a dialogue displayed on the user I/F of theterminal device.

FIG. 12 shows an example of a dialogue displayed on the user I/F of theterminal device.

FIG. 13 shows an example of a dialogue displayed on the user I/F of theterminal device.

FIG. 14 is a flowchart representing a control structure of a programexecuted by the multifunction peripheral shown in FIG. 1.

FIG. 15 shows a detailed flow of step S2000 of FIG. 14.

FIG. 16 shows a detailed flow of step S2120 of FIG. 14.

FIG. 17 shows an example of a screen image allowing wireless settingsdisplayed on a terminal device in accordance with a modification of thepresent invention.

FIG. 18 shows an example of a screen image allowing wireless settingsdisplayed on a multifunction peripheral in accordance with amodification of the present invention.

FIG. 19 shows an example of a screen image allowing wireless settingsdisplayed on a terminal device in accordance with another modificationof the present invention.

FIG. 20 shows an example of a screen image allowing wireless settingsdisplayed on a multifunction peripheral in accordance with anothermodification of the present invention.

DESCRIPTION OF EMBODIMENTS

In the following embodiments, the same components are denoted by thesame reference numerals. Their functions and names are also the same.Therefore, detailed descriptions thereof will not be repeated.

Overall System Configuration

Referring to FIG. 1, an overall configuration of an image forming system50 in accordance with the present embodiment will be described. Imageforming system 50 includes a multifunction peripheral (MFP) 100 as onetype of image forming apparatus, and a terminal device 200 that issues aprint request to MFP 100. MFP 100 has, for example, a copy function anda printer function. MFP 100 receives a print instruction from terminaldevice 200 and prints an image on a sheet of recording paper. Terminaldevice 200 is a smart phone. MFP 100 and terminal device 200 areconnected to be communicable with each other through a wireless link300.

When MFP 100 and terminal device 200 are connected by wireless link 300,it becomes difficult to maintain satisfactory communication betweenterminal device 200 and MFP 100 if the state of wireless link 300 (forexample, radio wave condition) deteriorates. In that case, satisfactorytransfer of image data from terminal device 200 to MFP 100 becomesdifficult.

Referring to FIG. 2, the state of connection of wireless link 300changes depending, for example, on the distance between terminal device200 and MFP 100. By way of example, when terminal device 200 moves awayfrom MFP 100, intensity of radio wave decreases. Even when terminaldevice 200 is within a communication range with MFP 100, if the terminaldevice is too far from MFP 100, the radio wave intensity becomes weakand communication tends to be lost. In the present embodiment, if thecommunication is about to be lost while image data is being transmittedfrom terminal device 200 to MFP 100, an alarm is displayed on terminaldevice 200 to notify the user of the bad radio wave condition. By thisnotification, the user is urged to move to a range of better radio waveintensity. As the user holding the terminal device 200 moves closer toMFP 100, the radio wave condition is improved.

Referring to FIG. 3, when MFP 100 and terminal device 200 are connectedby wireless link 300, it is impossible to visually recognize the rangein which communication is possible. Therefore, it is possible that theuser holding terminal device 200 unintentionally goes out of the rangeof communication with MFP 100. In such a situation, communication fails.If the communication fails while image data is being transmitted fromterminal device 200 to MFP 100, transfer of image data from terminaldevice 200 to MFP 100 becomes impossible. In the present embodiment, ifthe communication fails during transmission of image data from terminaldevice 200 to MFP 100, terminal device 200 and MFP 100 suspend theinterrupted state halfway through the communication. Therefore, whencommunication between terminal device 200 and MFP 100 resumes, it ispossible to restart printing from the interrupted point.

[Hardware Configuration]

<<MFP 100>>

Referring to FIG. 4, MFP 100 constituting the present image formingsystem 50 includes a control unit 110, an image reading unit 120, animage processing unit 130, an image forming unit 140, a wirelesscommunication unit 150 and an operation unit 160.

Control unit 110 is substantially a computer, including a CPU (CentralProcessing Unit) 112, an ROM (Read Only Memory) 114, an RAM (RandomAccess Memory) 116, and an HDD (Hard Disk Drive) 118. To CPU 112, a BUSline 170 is connected, and to BUS line 170, ROM 114, RAM 116 and HDD 118are electrically connected. CPU 112 executes various computer programsin accordance with instructions from operation unit 160 and the like,whereby desired processes such as operations of various units of MFP 100and communication with terminal device 200 are executed. The variouscomputer programs mentioned above are stored in advance in ROM 114 orHDD 118, and when a desired process is to be executed, the program orprograms are read from ROM 114 or HDD 118 and transferred to RAM 116.CPU 112 reads and interprets an instruction of a program from an addressin RAM 116, which is designated by a value stored in a register referredto as a program counter, not shown. Further, CPU 112 reads datanecessary for an operation from an address designated by the readinstruction, and executes a process corresponding to the instruction, onthe data. The result of execution is also stored in RAM 116, HDD 118 ora register or the like in CPU 112, at an address designated by aninstruction.

HDD 118 stores a computer program for realizing general operations ofMFP 100. The computer program is provided by an information processingapparatus or the like through a network or the like, not shown. Thecomputer program may be provided by a storage medium such as a DVD,having the computer program recorded thereon. Specifically, a DVD as amedium for recording the computer program may be mounted on a DVD drive(not shown) built in MFP 100, and the computer program may be read fromthe DVD and installed in HDD 118. HDD 118 also stores various dataincluding image data.

To BUS line 170, image reading unit 120, image processing unit 130,image forming unit 140, wireless communication unit 150 and operationunit 160 are further electrically connected.

Image reading unit 120 includes a document detection sensor and a CCD(Charge Coupled Device) line sensor (both not shown). The documentdetection sensor irradiates an image-bearing surface of a documentplaced on a platen (not shown) manually by the user or by an automaticdocument feeder (not shown) with light from a light source (not shown),and thereby obtains reflection light, and forms an image of the obtainedreflection light on the CCD line sensor. The CCD line sensor executesphoto-electric conversion of the formed reflection light imagesuccessively, and outputs the result as image data to image processingunit 130. Specifically, image reading unit 120 reads image informationfrom the document placed on the platen at the time of copying orscanning the document by the document detection sensor, converts theread image information to electric signals by the CCD line sensor, andoutputs the result as the image data to image processing unit 130.

Image processing unit 130 includes an MPU (Micro Processing Unit, notshown). Image processing unit 130 performs various processes including aprescribed image processing such as rasterization on the image datareceived from image reading unit 120, terminal device 200 or the like,and thereby creates print data of a prescribed tone, which is output toimage forming unit 140.

Image forming unit 140 is to print the image represented by the imagedata on a sheet of recording paper and, by way of example, it includes:a photoreceptor drum, a charger, a laser scanning unit (LSU), adeveloper, a transfer device, a cleaning device, a fixing device and aneutralizer. In image forming unit 140, a conveying path, for example,is provided and a sheet of recording paper fed from a paper feed unit(not shown) is conveyed along the conveying path. The paper feed unitdraws out sheets of recording paper stacked on a paper feed cassette(not shown) or on a manual feed tray one by one, and feeds the sheet ofpaper to the paper conveying path of image forming unit 140. While thesheet of recording paper is fed along the conveying path of imageforming unit 140, the sheet passes between the photoreceptor drum andthe transfer device, and further passes through the fixing device,whereby printing is done on the sheet of recording paper.

The photoreceptor drum rotates in one direction, and its surface iscleaned by the cleaning device and the neutralizer and, thereafter,uniformly charged by the charger. The laser scanning unit modulates thelaser beam based on the image data to be printed, and repeatedly scansthe surface of photoreceptor drum with the modulated laser beam in amain scanning direction, whereby an electrostatic latent image is formedon the surface of photoreceptor drum. The developer develops theelectrostatic latent image by supplying toner to the surface ofphotoreceptor drum, and thus, a toner image is formed on the surface ofphotoreceptor drum. The transfer device transfers the toner image on thesurface of photoreceptor drum to the sheet of recording paper passingbetween the transfer device and the photoreceptor drum.

The fixing device includes a heating roller for heating the sheet ofrecording paper and a pressure roller for pressing the sheet ofrecording paper. As the sheet of recording paper is heated by theheating roller and pressed by the pressure roller, the toner image thathas been transferred to the sheet of recording paper is fixed on thesheet. The sheet of recording paper discharged from the fixing device(printed sheet) is discharged to a paper discharge tray.

Wireless communication unit 150 provides an interface with wireless link300. MFP 100 communicates with an external device (in the presentembodiment, terminal device 200) through wireless communication unit150. MFP 100 can receive instruction signals instructing execution ofvarious processes such as a print job, from terminal device 200 throughwireless communication unit 150. Wireless communication unit 150 furthermeasures radio wave intensity of wireless link 300 and measures speed ofcommunication of wireless link 300. Further, wireless communication unit150 detects whether or not communication with terminal device 200 failsduring reception of image data transmitted from terminal device 200.

Operation unit 160 includes a touch-panel display 162. Touch-paneldisplay 162 is a touch-panel integrated type liquid crystal displaydevice, formed by stacking display panel 164 and touch-panel 166.Display panel 164 presents various pieces of information related to thestate of MFP 100 as well as states of various processes. Touch-paneldisplay 162 also provides an interactive operation interface with theuser. The interactive operation interface receives a user instructionrelated to the overall operation of MFP 100, displays the contents ofinstruction on display panel 164, and outputs a control signal inaccordance with the instruction to control unit 110 or to the MPU ofimage processing unit 130.

MFP 100 also has a quick print function of executing the print processwhile receiving the image data, and a print function of receiving imagedata first and executing the print process after reception of all imagedata is completed. Either of these functions can be set in MFP 100. Forexample, either of the functions can be set on a settings screen (notshown) displayed on operation unit 160 (display panel 164) of MFP 100.Specifically, when the quick print is to be set, the quick printfunction is turned ON, and if the quick print is not to be set, thequick print function is turned OFF. When the quick print function isturned OFF, the print function of executing the print process afterreception of all image data is completed is set. These print functionscan also be set by terminal device 200. In that case, MFP 100 changesthe setting of itself upon reception of the settings instruction(settings information) transmitted from terminal device 200.

MFP 100 further has a function of suspending the interrupted statehalfway through the communication, when it is detected thatcommunication is interrupted during reception of image data transmittedfrom terminal device 200. Specifically, while the MFP 100 is receivingthe image data transmitted from terminal device 200, if interruption ofcommunication is detected, MFP 100 stores the data representing theunfinished state of communication in HDD 118. The data representing theunfinished state of communication includes: time information when theprint job was received; identification information of terminal device200; identification information of image data that has been received;stop position when the reception of image data is stopped by theinterruption of communication; and the image data received before theinterruption of communication. The identification information ofterminal device 200 is, for example, a terminal ID or serial number ofthe terminal. The identification information of image data is, forexample, its file name. If the quick print is set, the print process isexecuted while receiving the image data and, therefore, the image datareceived before the interruption of communication is not stored in HDD118. Specifically, in this situation, the data representing theunfinished state of communication does not include the image datareceived before the interruption of communication.

The function of suspending the unfinished state of communication can beset in MFP 100. In the present embodiment, whether the unfinished stateof communication is to be suspended or not can be set on wirelesssettings screen 400 displayed on operation unit 160 (display panel 164)of MFP 100. Referring to FIG. 6, wireless setting screen 400 includes acheck box 410 to be checked when the data of the unfinishedcommunication is to be suspended (hereinafter also referred to as “datasuspension setting”) and a check box 420 to be checked when the data ofunfinished communication is not to be suspended.

Control unit 110 further has a timer function of measuring, if thecommunication is interrupted, elapsed time from the interruption.Control unit 110 detects whether the communication is resumed within aprescribed time period (for example, about 30 seconds to few minutes)after the interruption of communication. The prescribed time period canbe set arbitrarily. If data received before the interruption ofcommunication has been stored in HDD 118 and the communication is notresumed, the image data that has been stored in HDD 118 is discarded(deleted).

<<Terminal Device 200>>

Referring to FIG. 5, terminal device 200 constituting present imageforming system 50 includes a control unit 210, a storage device 220, auser interface (hereinafter referred to as user I/F) 230 and a wirelesscommunication unit 240.

Control unit 210 is substantially a computer and it includes a CPU 212,an ROM 214 and an RAM 216. To CPU 212, a BUS line 250 is connected. ToBUS line 250, ROM 214 and RAM 216 are electrically connected. CPU 212executes various computer programs in accordance with instructions fromuser I/F 230, and thereby executes desired processes includingoperations of various units of terminal device 200 and communicationwith an external device (in the present embodiment, MFP 100).

To BUS line 250, storage device 220, user I/F 230 and wirelesscommunication unit 240 are electrically connected. ROM 214, RAM 216,storage device 220, user I/F 230 and wireless communication unit 240 alloperate in cooperation under the control of CPU 212, and as the terminaldevice in accordance with the present embodiment, terminal device 200realizes processes of various applications. These applications realize,for example, the terminal device 200 of image forming system 50 that cansave time and labor when communication is restarted, if thecommunication should be interrupted while image data stored in terminaldevice 200 is being transmitted to MFP 100.

Storage device 220 includes, for example, a flash memory drive such asan SSD (Solid State Drive) (not shown). Storage device 220 stores theapplications mentioned above and computer programs for realizing generaloperations of terminal device 200. These computer programs and the likeare provided by an information processing apparatus or the like througha network or the like, not shown. These computer programs and the likemay be provided by a storage medium such as a DVD, having the computerprograms and the like recorded thereon. Besides, storage device 220stores various data including image data. Storage device 220 may includean HDD in place of, or in addition to the SSD.

User I/F 230 is implemented, for example, by an input/output deviceincluding an operation display device such as a touch-panel display.

Wireless communication unit 240 provides an interface with wireless link300. Terminal device 200 communicates with an external device (in thepresent embodiment, MFP 100) through wireless communication unit 150.Terminal device 200 can transmit instruction signals to instructexecution of various processes including a print job, to MFP 100 throughwireless communication unit 150. Further, wireless communication unit240 detects whether or not communication with terminal device 200 failsduring reception of image data transmitted from terminal device 200,under the control of control unit 210.

Further, wireless communication unit 240 measures radio wave intensityof wireless link 300 and measures speed of communication of wirelesslink 300. Terminal device 200 has a threshold value as a reference fordetermining whether the radio wave intensity decreased (or issufficiently high), stored in advance in ROM 214, RAM 216, storagedevice 220 or the like. Control unit 210 compares the radio waveintensity measured by wireless communication unit 240 with the thresholdvalue and thereby determines whether the radio wave intensity decreased.Further, if it is determined that the radio wave intensity decreased,control unit 210 displays a notification to that effect on user I/F 230.

The function of giving an alarm when the radio wave intensity decreases(the radio wave intensity becomes weak) can be set in terminal device200. In the present embodiment, wireless setting screen 500 displayed onuser I/F 230 of terminal device 200 is configured to allow setting ofwhether the alarm is to be given when the radio wave intensity is weak.Referring to FIG. 7, wireless settings screen 500 has, as the alarmsettings when the radio wave intensity is weak, a check box 510 to bechecked if the alarm is to be given, and a check box 520 to be checkedif the alarm is not to be given.

Further, terminal device 200 has a function of suspending, wheninterruption of communication is detected while it is transmitting imagedata to MFP 100, the unfinished state interrupted halfway through thecommunication. Specifically, if interruption of communication isdetected while image data is being transmitted to MFP 100, terminaldevice 200 stores the data indicating the unfinished state ofcommunication, and the time information (job start time) whentransmission of the print job was started, in storage device 220. Thedata indicating the unfinished state of communication includes the stoppoint when the transmission of image data was stopped because of theinterruption of communication

[Software Configuration]

Referring to FIG. 8, the control structure f a computer program executedby terminal device 200 for issuing a print request from terminal device200 to MFP 100 in the image forming system 50 of the present inventionwill be described. The program is activated when an operation forissuing a print request is done by the user.

The program includes: a step S1000 of executing a communication processwith MFP 100; a step S1010 executed after step S1000, of determiningwhether data suspended last time for the image data selected by the userremains in terminal device 200, and branching the flow of controldepending on the result of determination; a step S1020, executed if itis determined at step S1010 that no suspended data remains, ofdetermining whether or not the radio wave intensity of wireless link 300is sufficiently high, and branching the flow of control depending on theresult of determination; a step S1030, executed if it is determined atstep S1020 that the radio wave intensity is sufficiently high, oftransferring image data stored in terminal device 200 to MFP 100; and astep S1040, executed after step S1030, of determining whether or nottransfer of all data is completed, and branching the flow of controldepending on the result of determination.

At step S1010, determination is made as to whether or not thecommunication was interrupted during transmission of image data lasttime and the unfinished state of communication has been suspended. Atstep S1020, the radio wave intensity measured by wireless communicationunit 240 is compared with the threshold value stored in the ROM or thelike, to determine whether the radio wave intensity is higher than thethreshold value. If the radio wave intensity measured by wirelesscommunication unit 240 is larger than the threshold value, control unit210 determines that the radio wave intensity is sufficiently high. Onthe other hand, if the radio wave intensity measured by wirelesscommunication unit 240 is equal to or lower than the threshold value,control unit 210 determines that the radio wave intensity is notsufficiently high (radio wave intensity is weak (deteriorated)). At stepS1030, image data selected by the user is transmitted to MFP 100. Atstep S1040, if it is determined that transfer of all data is not yetcompleted, the control returns to step S1020 and if it is determinedthat transmission of all data is completed, the program ends.

The program further includes: a step S1050, executed if it is determinedat step S1010 that data suspended last time remains, of determiningwhether suspended data in MFP 100 (image data that had been receivedbefore the communication was interrupted) has been discarded or not, andbranching the flow of control depending on the result of determination;and a step S1060, executed if it is determined at step S1050 that thesuspended data in MFP 100 has been discarded, of notifying transmissionof image data from the start, and proceeding to step S1020.

At step S1060, a dialogue 600 shown in FIG. 10 is displayed on user I/F230 (touch-panel display) of terminal device 200. Referring to FIG. 10,on dialogue 600, a text such as “Data of last transmission has beendiscarded. Printing will be done anew” is displayed. At step S1060, thedata representing the unfinished state of communication suspended interminal device 200 at the time of last transmission of image data isdiscarded.

The program further includes: a step S1070, executed if it is determinedat step S1050 that the data suspended in MFP 100 is not discarded, ofdetermining whether the image data is to be transmitted from the middle,and branching the flow of control depending on the result ofdetermination; a step S1080, executed if it is determined at step S1070that the image data is to be transmitted from the middle, of notifyingMFP 100 that data transmission will be resumed from the middle; and astep S1090, executed after step S1080, of changing the setting totransmit the image data from the middle and proceeding to step S1020. Ifit is determined at step S1070 that the image data is not to betransmitted from the middle, the control proceeds to step S1020.

At step S1070, a dialogue 610 shown in FIG. 11 is displayed on user I/F230 (touch-panel display) of terminal device 200. Referring to FIG. 11,on dialogue 610, a text inquiring “Do you want to send image data fromthe middle?” and “YES” key 612 and “NO” key 614 are displayed. If theuser operates “YES” key 612, control unit 210 determines that the imagedata is to be transmitted from the middle. If the user operates “NO” key614, control unit 210 determines that the image data is not to betransmitted from the middle (the image data should be transmitted fromthe start). At step S1080, terminal device 200 transmits an instructionto send the image data from the middle (from the position where thetransmission stopped last time) to MFP 100.

The program further includes: a step S1100, executed if it is determinedat step S1020 that the radio wave intensity is insufficient, ofdetermining whether the communication is interrupted, and branching theflow of control depending on the result of determination; a step S1110,executed if it is determined at step S1100 that the communication is notinterrupted, of determining whether the setting of alarm indication isON or not, and branching the flow of control depending on the result ofdetermination; and a step S1120, executed if it is determined at stepS1110 that the setting of alarm indication is ON, of displaying amessage notifying weak radio wave intensity, and proceeding to stepS1030. If it is determined at step S1110 that the setting of alarmindication is not ON, the control proceeds to step S1030.

At step S1110, whether the setting of alarm indication is ON isdetermined, based on which of the check boxes 510 and 520 is checked onwireless setting screen 500 shown in FIG. 7. If check box 510 ischecked, control unit 210 determines that the alarm indication settingis ON. If check box 520 is checked, control unit 210 determines that thealarm indication setting is not ON (OFF).

At step S1120, a dialogue 620 shown in FIG. 12 is displayed on user I/F230 (touch-panel display) of terminal device 200. Referring to FIG. 12,on dialogue 620, a text such as “Radio wave is weak. You may be too farfrom MFP. Move closer and condition may be improved.” is displayed. Bydisplaying dialogue 620 as such, terminal device 200 notifies the userof the unsatisfactory radio wave condition, as an alarm related to thestate of wireless link.

The program further includes: a step S1130, executed if it is determinedat step S1100 that the communication is interrupted, of determiningwhether or not the unfinished state is to be suspended, and branchingthe flow of control depending on the result of determination; and a stepS1140, executed if it is determined at step S1130 that the unfinishedstate is to be suspended, of executing the suspending process and thenending the program. If it is determined at step S1130 that theunfinished state is not to be suspended, the program ends.

At step S1130, a dialogue 630 shown in FIG. 13 is displayed on user I/F230 (touch-panel display) of terminal device 200. Referring to FIG. 13,on dialogue 630, a text inquiring “Communication is interrupted duringtransfer of image data to MFP. Do you want to suspend the unfinishedstate to enable restart from the middle?”, a “YES” key 632 and a “NO”key 634 are displayed. If the user operates “YES” key 632, control unit210 determines that the unfinished state is to be suspended. If the useroperates “NO” key 634, control unit 210 determines that the unfinishedstate is not to be suspended.

FIG. 9 is a detailed flow of step S1000 shown in FIG. 8. Referring toFIG. 9, this routine includes: a step S1200 of executing a process ofconnecting to MFP 100 through wireless link 300; a step S1210, executedafter step S1200, of determining whether or not discard of suspendeddata is notified from MFP 100, and branching the flow of controldepending on the result of determination; and a step S1220, executed ifit is determined at step S1210 that the discard of suspended data isnotified from MFP 100, of storing the fact of discard of suspended dataof MFP 100 in, for example, storage device 220, and ending the routine.The routine also ends if it is determined at step S1210 that the datadiscard is not notified from MFP 100.

At step S1050 shown in FIG. 8, based on the information stored at stepS1220 of FIG. 9 that the suspended data of MFP 100 has been discarded,whether the suspended data of MFP 100 is discarded or not is determined.

Referring to FIG. 14, a control structure of a computer program executedby MFP 100 in image forming system 50 in accordance with the presentembodiment will be described. The program is activated when MFP 100 ispowered on.

The program includes: a step S2000 of executing a communication processwith terminal device 200; a step S2010, executed after step S2000, ofdetermining whether the quick print function is ON, and branching theflow of control depending on the result of determination; a step S2020,executed if it is determined at step S2010 that the quick print functionis ON, of printing while receiving the image data; a step S2030,executed if it is determined at step S2010 that the quick print functionis not ON, of only receiving the image data; and a step S2040, executedafter steps S2020 and S2030 of determining whether communication withterminal device 200 is interrupted, and branching the flow of controldepending on the result of determination.

The program further includes: a step S2050, executed if it is determinedat step S2040 that the communication is interrupted, of determiningwhether data suspension is set (whether the setting is to suspend datathat is being transmitted), and branching the flow of control dependingon the result of determination; a step S2060, executed if it isdetermined at step S2050 that the data suspension is set, of executing aprocess of suspending the unfinished state of communication (suspendingthe data that is being transmitted); a step S2070, executed after stepS2060, of determining whether or not communication is resumed within aprescribed time period from interruption, and branching the flow ofcontrol depending on the result of determination; and a step S2080,executed if it is determined at step S2070 that the communication isresumed within the prescribed time period, of determining whether or notthe operation is to be restarted with the interrupted data, andbranching the flow of control depending on the result of determination.

At step S2050, whether the setting is to suspend the data is determinedbased on which of the check boxes 410 and 420 is checked on wirelesssetting screen 400 shown in FIG. 6. If check box 410 is checked, controlunit 110 determines that the setting is to suspend the data. If checkbox 420 is checked, control unit 110 determines that data suspension isnot set.

The program further includes: a step S2090, executed if it is determinedat step S2080 that the communication is to be resumed with theinterrupted data, of receiving the image data from the middle (from theposition where transmission stopped last time); a step S2100, executedif it is determined at step S2050 that the data suspension is not set,and if it is determined at step S2070 that the communication is notresumed within the prescribed time period, of discarding the suspendedimage data; a step S2110, executed after step S2100, of cancellingprinting and ending the program; and a step S2120, executed if it isdetermined at step S2040 that the communication is not interrupted, ifit is determined at step S2080 that the communication is not to berestarted with the interrupted data, and after step S2090, of executinga process of outputting image data and ending the program.

FIG. 15 is a detailed flow of step S2000 of FIG. 14. Referring to FIG.15, the routine includes; a step S2200 of executing a process ofconnecting to terminal device 200 through wireless link 300; a stepS2210, executed after step S2200, of determining whether or not thesuspended image data is discarded, and branching the flow of controldepending on the result of determination; and a step S2220, executed ifit is determined at step S2210 that the suspended image data isdiscarded, of notifying terminal device 200 of the discard and endingthe routine. The routine also ends if it is determined at step S2210that the suspended image data is not discarded.

FIG. 16 is a detailed flow of step S2120 of FIG. 14. Referring to FIG.16, the routine includes: a step S2300 of determining whether the quickprint is set (ON), and branching the flow of control depending on theresult of determination; a step S2310, executed if it is determined atstep S2300 that the quick print is set, of determining whether printingis completed, and branching the flow of control depending on the resultof determination; a step S2320, executed if it is determined at stepS2300 that the quick print is not set, of determining whether receptionof all data is completed, and branching the flow of control depending onthe result of determination; and a step S2330, executed if it isdetermined at step S2320 that reception of all data is completed, ofexecuting the print process based on the received image data and endingthe routine.

If it is determined at step S2310 that printing is completed, theroutine ends. On the other hand, if it is determined at step S2310 thatprinting is not yet completed, the control returns to step S2040 shownin FIG. 14. Similarly, the control returns to step S2320 shown in FIG.14, if it is determined at step S2320 that reception of all data is notyet completed.

[Operation]

Referring to FIGS. 1 to 3 and 8 to 16, the operation of image formingsystem 50 in accordance with the present embodiment based on thestructures and flowcharts as above will be described.

Referring to FIG. 1, a user of terminal device 200 operates terminaldevice 200 to execute printing on MFP 100. Terminal device 200communicates in wireless manner with MFP 100, and establishes connectionwith MFP 100 through wireless link 300. When the user selects an imagedata, terminal device 200 issues a print request. Terminal device 200determines whether or not radio wave intensity is sufficiently high, andif the radio intensity is sufficiently high (YES at step S1020 shown inFIG. 8), transmits the selected image data to MFP 100 (step S1030).Terminal device 200 continues sending image data until transmission ofall data is completed.

If MFP 100 is set to do quick printing (YES at step S2010 shown in FIG.14), MFP 100 prints while receiving the image data from terminal device200 (step S2020). When reception of all data transmitted from terminaldevice 200 is completed and printing ends (YES at step S2310 shown inFIG. 16), the operation of image forming system 50 ends. If quickprinting is not set (NO at step S2010 shown in FIG. 14), only thereception of image data takes place (step S2030), and when reception ofall data is completed (YES at step S2320 shown in FIG. 16), the printprocess is executed (step S2330). When the print process ends, theoperation of image forming system 50 ends.

Referring to FIG. 2, if radio wave intensity decreases duringtransmission of image data from terminal device 200 to MFP 100 (NO atstep S1020 shown in FIG. 8) and the communication is about to be lost(NO at step S1100), terminal device 200 determines whether or not thealarm display setting is ON (step S1110). If the alarm display settingis ON (YES at step S1110), terminal device 200 displays the dialogue 620shown in FIG. 12 on user I/F 230, and thereby notifies the user of thebad radio wave condition (step S1120). In this situation, terminaldevice 200 continues transmission of image data (step S1030). If theuser recognizes the bad condition of radio wave by this notification(alarm) and moves closer to MFP 100, the radio wave condition will beimproved. If the alarm display setting is not ON (NO at step S1110),terminal device 200 continues transmission of image data withoutdisplaying the dialogue 620 on user I/F 230 (step S1030).

Referring to FIG. 3, if the communication is interrupted while imagedata is being transmitted from terminal device 200 to MFP 100 (YES atstep S1100 shown in FIG. 8), terminal device 200 displays the dialogue630 shown in FIG. 13 on user I/F 230, to have the user select whetherthe unfinished state is to be suspended. When the user operates “YES”key 632 on dialogue 630, terminal device 200 determines that theunfinished state is to be suspended, and executes the suspending process(step S1140 shown in FIG. 8). Specifically, terminal device 200 storesthe stop position when transmission of image data is stopped as thecommunication is interrupted. When the user operates “NO” key 634,terminal device 200 determines that the unfinished state is not to besuspended, and ends the operation of transmitting the image data.

That the communication is interrupted on the side of terminal device 200also means that the communication is interrupted on the side of MFP 100.If an interruption of communication with terminal device 200 is detected(YES at step S2040 shown in FIG. 14), MFP 100 determines whether it isset to suspend data (step S2050), and if it is set to suspend data, itsuspends the unfinished state of communication (step S2060). When acommunication is interrupted, MFP 100 starts counting of elapsed timefrom the interruption.

Assume that after the communication was interrupted during transmissionof image data, the user of terminal device 200 tries to transmit theimage data again, within a prescribed time period from the interruptionof communication. If the communication is resumed within the prescribedtime period (YES at step S2070 shown in FIG. 14), the suspended imagedata is not yet discarded, as will be described later.

When terminal device 200 communicates with MFP 100 again (step S1000shown in FIG. 8), terminal device 200 determines that the data suspendedlast time remains in terminal device 200 (YES at step S1010). Terminaldevice 200 displays dialogue 610 shown in FIG. 11 on user I/F 230, tohave the user select whether the image data is to be transmitted fromthe middle. If the user operates “YES” key 612 on dialogue 610, terminaldevice 200 determines that the image data is to be transmitted from themiddle (YES at step S1070). Then, terminal device 200 transmits aninstruction to MFP 100 that the image data will be transmitted from themiddle (from the position interrupted last time) (step S1080).Thereafter, terminal device 200 changes the settings of itself to enabletransmission of image data from the middle (step S1090), and thus,transmits the image data from the middle.

Upon reception of the instruction from terminal device 200, MFP 100determines that the communication will be resumed with the data from themiddle (YES at step S2080 shown in FIG. 14), and receives the image datafrom the middle (from the position interrupted last time) (step S2090).If quick print is set in MFP 100 (YES at step S2300 shown in FIG. 16),printing is done while image data is being received. When printing ends(YES at step S2310), the operation of image forming system 50 ends. Ifthe quick print is not set in MFP 100 (NO at step S2300 shown in FIG.16), then, after reception of all data including the image datasuspended last time is completed (YES at S2320), the process forprinting the received image data is executed (step S2330). When printingends, the operation of image forming system 50 ends.

On the other hand, if the user operates “NO” key 614 on dialogue 610shown in FIG. 11, terminal device 200 determines that the image data isnot to be transmitted from the middle (image data is to be transmittedfrom the start) (NO at step S1070 shown in FIG. 8). Here, the setting isnot changed to transmit the image data from the middle and, hence,terminal device 200 transmits the image data from the start (stepS1030). MFP 100 determines that the communication is not resumed withthe interrupted data (NO at step S2080 shown in FIG. 14), and receivesthe image data from the start. After receiving the image data, MFP 100executes the print process based on the image data.

In order to prevent data representing unfinished state of communicationfrom being continuously accumulated in terminal device 200 because ofthe suspending process (step S1140), terminal device 200 deletes dataafter a prescribed time period from the start time of the correspondingjob.

On the other hand, if terminal device 200 does not transmit the imagedata within the prescribed time period after the interruption ofcommunication (NO at step S2070 shown in FIG. 14), MFP 100 discards theimage data that has been suspended (step S2100), and cancels printing(step S2110).

Assume that the user of terminal device 200 tries to transmit the sameimage data, after the lapse of the prescribed time period from theinterruption of communication. Here, when connected to terminal device200, MFP 100 notifies terminal device 200 of the fact that the imagedata has been discarded (step S2220 shown in FIG. 15). Receiving thenotification that the image data has been discarded (YES at step S1210shown in FIG. 9), terminal device 200 stores the fact that the imagedata that had been suspended in MFP 100 is discarded (step S1220).

Even though the data suspended last time remains in terminal device 200(YES at step S1010 shown in FIG. 8), if the image data that had beensuspended in MFP 100 is discarded (YES at step S1050), terminal device200 displays dialogue 600 shown in FIG. 10 on user I/F 230 to notify theuser that the image data is to be transmitted from the start (printingis to be done anew), since the image data that had been suspended in MFP100 is discarded. Thereafter, terminal device 200 deletes the datasuspended last time, from terminal device 200.

If the image data that had been suspended in MFP 100 is discarded, it isimpossible to resume communication with the interrupted data. In thissituation, the data suspended last time still remains in terminal device200 and, hence, it may be possible that the user of terminal device 200erroneously assumes that the image data up to the point of interruptionis still kept in MFP 100, and requests MFP 100 to restart with theinterrupted data.

In the present embodiment, the user is notified of the discard of imagedata that had been suspended in MFP 100 and, therefore, the user becomesaware that restart with the interrupted data is impossible. Thus, theproblem mentioned above possibly caused by misrecognition can beprevented.

[Effects of the Present Embodiment]

As is apparent from the description above, use of image forming system50 in accordance with the present embodiment attains the followingeffects.

The present image forming system 50 detects whether or not communicationbetween MFP 100 and terminal device 200 is interrupted. If interruptionof communication is detected while image data is being transmitted fromterminal device 200 to MFP 100, the present image forming system 50suspends the unfinished state of communication interrupted halfwaythrough. Specifically, in the present image forming system 50, when thecommunication is interrupted, the unfinished state of communication (thestate at the time point when communication is interrupted) is recorded.Therefore, when the communication resumes (recovers), data transfer canbe restarted from the middle and, therefore, time and labor for restartcan be saved.

Assume that image data is being transmitted from terminal device 200 toMFP 100 and the user using terminal device 200 moves out of the range ofwireless communication while holding terminal device 200. Then, thecommunication is interrupted. In such a situation, the unfinished stateof communication is suspended in the present image forming system 50.Therefore, when the user moves back to the range allowing wirelesscommunication and the communication resumes, data communication can berestarted from the middle. Thus, time and labor at the time of restartcan efficiently be saved.

Further, assume that image data of large data size is to be transmittedfrom terminal device 200 to MFP 100 through wireless link 300. In aconventional system, the user using terminal device 200 cannot go out ofthe range of wireless communication and if he/she should go out of therange of wireless communication and the communication is interrupted,data communication must be done again from the start. In contrast, inthe present image forming system 50, even when the user goes out of therange allowing wireless communication and the communication isinterrupted, data communication can be restarted from the middle and,therefore, the user can move freely with terminal device 200.

Further, when the radio wave condition of wireless link 300deteriorates, for example, terminal device 200 notifies the user of thebad radio wave condition as an alarm related to the state of wirelesslink. By this notification, the user becomes aware of the state ofwireless link 300 (that the radio wave condition is bad). Thus, byurging the user to move to a range of better radio wave condition, forexample, it is possible to attain better radio wave condition.

Further, if it is detected that communication is interrupted while imagedata is being transmitted from terminal device 200 to MFP 100, terminaldevice 200 displays dialogue 630 on user I/F 230 to ask the user if theunfinished state of communication is to be suspended. Therefore, it ispossible for the user to select whether the unfinished state ofcommunication is to be suspended or not. The unfinished state ofcommunication can be suspended only when the user so wishes.

In the present image forming system 50, if interruption of communicationis detected while image data is being transmitted from terminal device200 to MFP 100, both terminal device 200 and MFP 100 suspend theunfinished state of communication. Since terminal device 200 suspendsthe unfinished state of transmission of image data halfway through, itis possible for terminal device 200 to easily transmit the image datafrom the middle when the communication is resumed. Further, since MFP100 suspends the unfinished state of reception of image data halfwaythrough, it is possible for MFP 100 to easily receive the image datafrom the middle when the communication is resumed.

MFP 100 measures the lapsed time after the detection of interruption ofcommunication. If the communication resumes within a prescribed timeperiod from the detection of interruption of communication, MFP 100receives the image data from the suspended, unfinished state ofcommunication. If the communication does not resume within theprescribed time period after the detection of interruption ofcommunication, MFP 100 discards the received image data. It is likelythat data transmission is resumed, if it is within a prescribed timeperiod from when interruption of communication is detected. Therefore,MFP 100 is configured to be able to receive image data from thesuspended unfinished state of communication, if the communicationrestarts within a prescribed time period from the detection ofinterruption of communication. On the other hand, if the prescribed timeperiod passed from when interruption of communication was detected, itis unlikely that the data transmission restarts, or it is more likelythat the data transmission is started anew. Therefore, MFP 100 discardsthe received image data if communication is not resumed within aprescribed time period from when the link state detecting means detectedthe interruption of communication. Thus, wasteful use of storage areafor storing image data can be avoided.

MFP 100 has the print function of starting image formation (printing)after reception of image data is completed. If this print function isselected, MFP 100 does not start printing until all data are received.Therefore, even when communication is interrupted during transfer of theimage data and the data communication is restarted from the middle whenthe communication resumes, it is possible to prevent the sheets of printoutputs dispersed (separated). This also saves time and labor at thetime of restart.

[Modifications]

Though an example in which the present invention is applied to an MFP asone type of image forming apparatus has been described in the embodimentabove, the present invention is not limited to such an embodiment. Theimage forming apparatus constituting the present image forming systemmay be an apparatus other than the MFP. By way of example, it may be aprinting device having only the printing function.

Though an example in which the present invention is applied to a smartphone as a terminal device has been described in the embodiment above,the present invention is not limited to such an embodiment. The terminaldevice constituting the present image forming system may be any terminaldevice other than the smart phone provided that it is capable oftransmitting image data to the image forming apparatus. The terminaldevices other than the smart phone may include, for example, a portabletelephone, a PDA (Personal Digital Assistant), a note-book type personalcomputer (hereinafter referred to as “PC”), an unportable PC (such as adesk-top PC), a tablet terminal and the like.

Though an example in which the terminal device and the MFP are connectedto enable communication via wireless link has been described in theembodiment above, the present invention is not limited to such anembodiment. By way of example, the terminal device and the image formingapparatus may be connected to enable communication via wiredcommunication link. Even when these are connected in wired manner,communication may be interrupted by some cause or other. Even in such acase, the time and labor can be saved at the restart of communication byapplying the present invention.

Though an example in which the unfinished state of communication issuspended both by the terminal device and the MFP when communication isinterrupted has been described in the embodiment above, the presentinvention is not limited to such an embodiment. By way of example, whenthe communication is interrupted, the unfinished state of communicationmay be suspended only by the MFP. In that case, the MFP may store theterminal information of the terminal device as the source oftransmission of image data and information related to the suspension,and the

MFP may notify the terminal device of the information of suspension atthe time of next communication (connection), so as to allow the user toselect whether the suspended printing is to be restarted or not.

Though an example in which the setting as to whether the unfinishedstate of communication is to be suspended or not in the MFP is done onthe side of the MFP has been described in the embodiment above, thepresent invention is not limited to such an embodiment. The setting asto whether the unfinished state of communication is to be suspended ornot in the MFP may be done on the side of the terminal device, or may bedone both by the terminal device and the MFP. If the setting is on theside of the terminal device, for example, a piece of information as towhether suspension is to be done or not is sent from the terminal deviceto the MFP at the first communication (connection) with the MFP.Receiving this notification from the terminal device, the MFP operatesas notified.

When the setting as to whether the unfinished state of communication isto be suspended or not in the MFP is to be done both by the terminaldevice and the MFP, a wireless setting screen is displayed in each ofthese. Referring to FIG. 17, a wireless setting screen 700 is displayedon the user I/F of the terminal device. Wireless setting screen 700includes a check box 702 to be checked when the data of unfinishedcommunication is to be suspended, a check box 704 to be checked when thedata of unfinished communication is not to be suspended, and a check box706 to be checked when the setting on the side of MFP is to be followed.Referring to FIG. 18, a wireless setting screen 750 is displayed on anoperation unit (display panel) of the MFP. Wireless setting screen 750includes a check box 752 to be checked when the data of unfinishedcommunication is to be suspended, and a check box 754 to be checked whenthe data of unfinished communication is not to be suspended. If thesetting on the MFP is different from that on the terminal device, thesetting on the MFP may be given priority, or the setting on the terminaldevice may be given priority.

Though an example in which the setting as to whether the alarm displayis to be given on the terminal device when the radio wave intensity islow is done on the side of the terminal device has been described in theembodiment above, the present invention is not limited to such anembodiment. The setting as to whether the alarm display is to be givenon the terminal device may be done on the side of MFP (image formingapparatus) or may be done both by the MFP and the terminal device. Ifthe setting is to be done on the side of MFP, for example, a piece ofinformation as to whether the alarm display is to be given is sent fromthe MFP to the terminal device at the first communication (connection)with the terminal device. Receiving this notification from the MFP, theterminal device operates as notified.

If the setting as to whether the alarm display is to be given is to bedone both by the terminal device and the MFP, a wireless setting screenis displayed in each of these. Referring to FIG. 19, a wireless settingscreen 800 is displayed on the user I/F of the terminal device. Wirelesssetting screen 800 includes, as the setting for alarm when the radiowave intensity is low, a check box 802 to be checked when the alarm isto be given, a check box 804 to be checked when the alarm is not to begiven and a check box 806 to be checked when the setting on the side ofMFP is to be followed. Referring to FIG. 20, a wireless setting screen850 is displayed on operation unit (display panel) of the MFP. Wirelesssetting screen 850 includes, as the setting for alarm when the radiowave intensity is low, a check box 852 to be checked when the alarm isto be given, and a check box 854 to be checked when the alarm is not tobe given. If the setting on the MFP is different from that on theterminal device, the setting on the MFP may be given priority, or thesetting on the terminal device may be given priority.

Though an example in which a dialogue is displayed on the terminaldevice to notify the user of bad radio wave condition when the radiowave condition of wireless link deteriorates has been described in theembodiment above, the notification to the user may utilize at least oneof alarm sound and vibration, in addition to the display of dialogue.

In the embodiment above, the image forming system may be linked tocloud. By way of example, the MFP may be connected to a server on anetwork to enable communication, and the suspended data in the MFP maybe transferred to the cloud (server) if the data is not used after aprescribed time period. When the terminal device transmits the imagedata from the middle, the terminal device may notify not the MFP but theserver of the fact that transmission will be restarted from theinterrupted data. In this manner, by saving the suspended data in aserver on a network, the burden on the HDD (storage) of the MFP can bealleviated. Further, by saving the suspended data on a server on anetwork, it becomes possible to restart printing from the middle by adifferent MFP.

The embodiments as have been described here are mere examples and shouldnot be interpreted as restrictive. The scope of the present invention isdetermined by each of the claims with appropriate consideration of thewritten description of the embodiments and embraces modifications withinthe meaning of, and equivalent to, the languages in the claims.

INDUSTRIAL APPLICABILITY

By the present invention, an image forming apparatus and the like thatcan save time and labor at the time of restarting communication, evenwhen communication is interrupted during transfer of image data, can beprovided.

REFERENCE SIGNS LIST

-   50 image forming system-   100 MFP-   110 control unit-   120 image reading unit-   130 image processing unit-   140 image forming unit-   150, 240 wireless communication unit-   160 operation unit-   200 terminal device-   210 control unit-   220 storage device-   230 user I/F-   300 wireless link-   400, 500 wireless setting screen-   600˜630 dialogue

1. (canceled)
 2. An image forming apparatus, connected to a terminaldevice through a communication link including a wireless link, receivingimage data transmitted from the terminal device and forming an imagebased on the image data, the image forming apparatus comprising: awireless communicator that communicates with the terminal device throughthe wireless link; a link state detector that detects a state of thewireless link; and a notification setting means for setting the terminaldevice to notify a user of a method of improving radio wave intensity,when the radio wave intensity of the wireless link becomes equal to orlower than a prescribed threshold value.
 3. The image forming apparatusaccording to claim 2, wherein the wireless communicator receives imagedata transmitted from the terminal device even when the terminal deviceis notifying the user of the method of improving radio wave intensity asthe radio wave intensity of the wireless link becomes equal to or lowerthan the prescribed threshold value while the wireless communicator isreceiving the image data transmitted from the terminal device.
 4. Theimage forming apparatus according to claim 2, wherein the image formingapparatus further includes a data suspending unit, responsive todetection by the link state detector of an interruption of communicationwhile the image data transmitted from the terminal device is beingreceived, for suspending the reception by recording an unfinished stateof reception of the image data; and the wireless communicator resumesreception of the image data from a position where communication has beeninterrupted of the image data that was being received, based on thestate recorded in said data suspending unit, in accordance with theresult of detection by said link state detector.
 5. The image formingapparatus according to claim 2, further comprising: a timer thatmeasures time elapsed after the detection of the interruption ofcommunication by the link state detector; and a receiver that receives,when the image forming apparatus is suspending an unfinished state ofcommunication and communication is resumed within a prescribed timeperiod from the detection of the interruption of communication by thelink state detector, the image data from the suspended unfinished state;wherein the image forming apparatus discards the received image data,when the image forming apparatus is suspending an unfinished state ofcommunication and communication is not resumed within a prescribed timeperiod from the detection of the interruption of communication by thelink state detector.
 6. The image forming apparatus according to claim2, wherein the image forming apparatus starts image formation afterreception of image data is completed.
 7. A terminal device, connected toan image forming apparatus through a wireless link, the terminal devicecomprising: a transmitter that transmits image data to the image formingapparatus; and a link state detector that detects a state of thewireless link; wherein the terminal device detects the state of thewireless link and determines whether the radio wave intensity of thedetected state of the link is equal to or lower than a prescribedthreshold value; the terminal device, in response to the radio waveintensity of the detected state of the link being equal to or lower thana prescribed threshold value, notifies a user of a method of improvingradio wave intensity.
 8. The terminal device according to claim 7,wherein the transmitter transmits image data to the image formingapparatus even when the method of improving radio wave intensity isbeing notified as the radio wave intensity of the wireless link becomesequal to or lower than the prescribed threshold value while the imagedata is being transmitted to said image forming apparatus.
 9. Theterminal device according to claim 7, further comprising: a wirelesslink state detector that detects a state of the wireless link; and analarm that provides an alarm notice related to the state of the wirelesslink in accordance with the state of wireless link detected by thewireless link state detector while image data is being transmitted tothe image forming apparatus.
 10. The terminal device according to claim7, further comprising an inquiry unit, responsive to detection by thelink state detector of an interruption of communication with said imageforming apparatus, for making an inquiry as to whether or not anunfinished state of transmission of said image data is to be recorded; adisplay that displays the inquiry in response to an instruction from theinquiry unit; and a selective executing unit that selectively executes,in response to an instruction input to the inquiry displayed on thedisplay, a process of suspending or a process of not suspendingcommunication.
 11. An image forming system, including a terminal devicetransmitting image data, and an image forming apparatus connected to theterminal device through a communication link including a wireless link,receiving the image data transmitted from the terminal device andforming an image based on the image data, the image forming systemcomprising: a link state detector that detects a state of the wirelesslink; wherein each of the terminal device and the image formingapparatus includes wireless communicators that communicate with eachother through the wireless link; the terminal device detects the stateof the wireless link and determines whether radio wave intensity of thedetected state of the wireless link is equal to or lower than aprescribed threshold value; the terminal device notifies a user of amethod of improving radio wave intensity when the radio wave intensityof the wireless link becomes equal to or lower than the prescribedthreshold value; and the image forming further apparatus includes asetting screen that is used to set the terminal device to notify theuser of the method of improving radio wave intensity when the radio waveintensity of the wireless link becomes equal or lower than theprescribed threshold value.
 12. The image forming system according toclaim 11, wherein the wireless communicator conducts transmission ofimage data from the terminal device and reception of image data from theimage forming apparatus, even when the terminal device is notifying theuser of the method of improving radio wave intensity when the radio waveintensity of the wireless link becomes equal to or lower than theprescribed threshold value while the image data is being transmitted andreceived between the image forming apparatus and the terminal device.13. The image forming system according to claim 11, wherein the imageforming apparatus suspends an unfinished state of receiving the imagedata.
 14. The image forming system according to claim 11, wherein theimage forming apparatus suspends an unfinished state of receiving theimage data, and the terminal device suspends an unfinished state oftransmitting the image data.
 15. A non-transitory computer readablemedium containing a computer program, causing a computer connected to animage forming apparatus through a communication link including awireless link to function as: a transmitter that transmits image data tothe image forming apparatus; a link state detector that detects a stateof the wireless link; a radio wave intensity determiner that detects astate of the wireless link and determines whether a radio wave intensityof the detected state of wireless link is equal to or lower than aprescribed threshold value; a notifier that, responsive to the radiowave intensity of the detected state of wireless link being equal to orlower than the prescribed threshold value, notifies a user of a methodof improving radio wave intensity; wherein the notifier is set to notifythe user of the method of improving radio wave intensity in accordancewith an instruction from the image forming apparatus.